Fuel vapor storage and recovery apparatus with heat exchanger

Abstract

A fuel vapor storage and recovery apparatus for a fuel system of a motor vehicle including an internal combustion engine with an exhaust pipe and a fuel tank containing a fuel vapor / air mixture above a liquid fuel, the exhaust pipe being close to the fuel tank. The apparatus includes a vapor storage canister including a fuel vapor adsorbent material therein, a thermal insulation mechanism for thermally insulating at least a portion of the fuel tank from the heat generated by the exhaust pipe, and a beat exchanger. The heat exchanger is configured to heat to a purge temperature air guided there through by absorbing heat from the thermal insulation mechanism.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the invention[0002]The invention relates to a fuel vapour storage and recovery apparatus for the fuel system of a motor vehicle comprising a vapour storage canister containing adsorbent material, which is intended to trap and store vapours from the vehicle's fuel tank, and to purge stored vapour and condensate during operation of the vehicle's engine.[0003]2. Discussion of the Background[0004]Fuel vapour escaping from the fuel system is a source of hydrocarbon emission from the automobile. In particular, gasoline vapours may escape from the external vents of the fuel tank, either while driving or while at rest. Within the past several years a number of attempts have been made to limit the escape of gasoline into the atmosphere.[0005]There have been proposed evaporative emission control systems that involve the use of charcoal-filled canisters which are connected, through vapour lines, to the fuel tanks such that gasoline vapours from the ...

AI Technical Summary

Benefits of technology

"The present invention is about a fuel vapour storage and recovery apparatus for vehicles with an internal combustion engine. The invention uses a heat shield to locate an air heater close to the fuel tank, which helps to heat the air guided through the heat exchanger. The heat exchanger is a separate piece of equipment that can be located above or below the fuel tank. The invention also includes a system for insulating the fuel tank from the heat generated by the exhaust pipe, which can be made of polymeric material like HDPE. The fuel vapour adsorbent material inside the canister can be charcoal or other absorbents. The heat insulating means can be metal heat shields or other suitable materials. The invention also includes a fuel tank system with a heat exchanger located close to the fuel tank and fuel vapour storage and recovery apparatus. The system includes a conduit system for connecting all its elements together."

Problems solved by technology

Such a system has the drawback of presenting bad adsorption performances when the engine is running, because it is permanently heated then and that fuel vapours rather tend to desorb when temperature rises (see above).

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